1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * PFCP according to 3GPP TS 29.244 4 * 5 * Copyright (C) 2022, Intel Corporation. 6 */ 7 8 #include <linux/module.h> 9 #include <linux/netdevice.h> 10 #include <linux/rculist.h> 11 #include <linux/skbuff.h> 12 #include <linux/types.h> 13 14 #include <net/udp.h> 15 #include <net/udp_tunnel.h> 16 #include <net/pfcp.h> 17 18 struct pfcp_dev { 19 struct list_head list; 20 21 struct sock *sk; 22 struct net_device *dev; 23 struct net *net; 24 25 struct gro_cells gro_cells; 26 }; 27 28 static unsigned int pfcp_net_id __read_mostly; 29 30 struct pfcp_net { 31 struct list_head pfcp_dev_list; 32 struct mutex lock; 33 }; 34 35 static void 36 pfcp_session_recv(struct pfcp_dev *pfcp, struct sk_buff *skb, 37 struct pfcp_metadata *md) 38 { 39 struct pfcphdr_session *unparsed = pfcp_hdr_session(skb); 40 41 md->seid = unparsed->seid; 42 md->type = PFCP_TYPE_SESSION; 43 } 44 45 static void 46 pfcp_node_recv(struct pfcp_dev *pfcp, struct sk_buff *skb, 47 struct pfcp_metadata *md) 48 { 49 md->type = PFCP_TYPE_NODE; 50 } 51 52 static int pfcp_encap_recv(struct sock *sk, struct sk_buff *skb) 53 { 54 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 55 struct metadata_dst *tun_dst; 56 struct pfcp_metadata *md; 57 struct pfcphdr *unparsed; 58 struct pfcp_dev *pfcp; 59 60 if (unlikely(!pskb_may_pull(skb, PFCP_HLEN))) 61 goto drop; 62 63 pfcp = rcu_dereference_sk_user_data(sk); 64 if (unlikely(!pfcp)) 65 goto drop; 66 67 unparsed = pfcp_hdr(skb); 68 69 ip_tunnel_flags_zero(flags); 70 tun_dst = udp_tun_rx_dst(skb, sk->sk_family, flags, 0, 71 sizeof(*md)); 72 if (unlikely(!tun_dst)) 73 goto drop; 74 75 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 76 if (unlikely(!md)) 77 goto drop; 78 79 if (unparsed->flags & PFCP_SEID_FLAG) 80 pfcp_session_recv(pfcp, skb, md); 81 else 82 pfcp_node_recv(pfcp, skb, md); 83 84 __set_bit(IP_TUNNEL_PFCP_OPT_BIT, tun_dst->u.tun_info.key.tun_flags); 85 tun_dst->u.tun_info.options_len = sizeof(*md); 86 87 if (unlikely(iptunnel_pull_header(skb, PFCP_HLEN, skb->protocol, 88 !net_eq(sock_net(sk), 89 dev_net(pfcp->dev))))) 90 goto drop; 91 92 skb_dst_set(skb, (struct dst_entry *)tun_dst); 93 94 skb_reset_network_header(skb); 95 skb_reset_mac_header(skb); 96 skb->dev = pfcp->dev; 97 98 gro_cells_receive(&pfcp->gro_cells, skb); 99 100 return 0; 101 drop: 102 kfree_skb(skb); 103 return 0; 104 } 105 106 static void pfcp_del_sock(struct pfcp_dev *pfcp) 107 { 108 udp_tunnel_sock_release(pfcp->sk); 109 pfcp->sk = NULL; 110 } 111 112 static void pfcp_dev_uninit(struct net_device *dev) 113 { 114 struct pfcp_dev *pfcp = netdev_priv(dev); 115 116 gro_cells_destroy(&pfcp->gro_cells); 117 pfcp_del_sock(pfcp); 118 } 119 120 static int pfcp_dev_init(struct net_device *dev) 121 { 122 struct pfcp_dev *pfcp = netdev_priv(dev); 123 124 pfcp->dev = dev; 125 126 return gro_cells_init(&pfcp->gro_cells, dev); 127 } 128 129 static const struct net_device_ops pfcp_netdev_ops = { 130 .ndo_init = pfcp_dev_init, 131 .ndo_uninit = pfcp_dev_uninit, 132 .ndo_get_stats64 = dev_get_tstats64, 133 }; 134 135 static const struct device_type pfcp_type = { 136 .name = "pfcp", 137 }; 138 139 static void pfcp_link_setup(struct net_device *dev) 140 { 141 dev->netdev_ops = &pfcp_netdev_ops; 142 dev->needs_free_netdev = true; 143 SET_NETDEV_DEVTYPE(dev, &pfcp_type); 144 145 dev->hard_header_len = 0; 146 dev->addr_len = 0; 147 148 dev->type = ARPHRD_NONE; 149 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 150 dev->priv_flags |= IFF_NO_QUEUE; 151 152 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 153 netif_keep_dst(dev); 154 } 155 156 static struct sock *pfcp_create_sock(struct pfcp_dev *pfcp) 157 { 158 struct udp_tunnel_sock_cfg tuncfg = {}; 159 struct udp_port_cfg udp_conf = { 160 .local_ip.s_addr = htonl(INADDR_ANY), 161 .family = AF_INET, 162 }; 163 struct net *net = pfcp->net; 164 struct socket *sock; 165 int err; 166 167 udp_conf.local_udp_port = htons(PFCP_PORT); 168 169 err = udp_sock_create(net, &udp_conf, &sock); 170 if (err) 171 return ERR_PTR(err); 172 173 tuncfg.sk_user_data = pfcp; 174 tuncfg.encap_rcv = pfcp_encap_recv; 175 tuncfg.encap_type = 1; 176 177 setup_udp_tunnel_sock(net, sock->sk, &tuncfg); 178 179 return sock->sk; 180 } 181 182 static int pfcp_add_sock(struct pfcp_dev *pfcp) 183 { 184 pfcp->sk = pfcp_create_sock(pfcp); 185 186 return PTR_ERR_OR_ZERO(pfcp->sk); 187 } 188 189 static int pfcp_newlink(struct net_device *dev, 190 struct rtnl_newlink_params *params, 191 struct netlink_ext_ack *extack) 192 { 193 struct net *link_net = rtnl_newlink_link_net(params); 194 struct pfcp_dev *pfcp = netdev_priv(dev); 195 struct pfcp_net *pn; 196 int err; 197 198 pfcp->net = link_net; 199 200 err = pfcp_add_sock(pfcp); 201 if (err) { 202 netdev_dbg(dev, "failed to add pfcp socket %d\n", err); 203 goto exit_err; 204 } 205 206 err = register_netdevice(dev); 207 if (err) { 208 netdev_dbg(dev, "failed to register pfcp netdev %d\n", err); 209 goto exit_del_pfcp_sock; 210 } 211 212 pn = net_generic(link_net, pfcp_net_id); 213 214 mutex_lock(&pn->lock); 215 list_add(&pfcp->list, &pn->pfcp_dev_list); 216 mutex_unlock(&pn->lock); 217 218 netdev_dbg(dev, "registered new PFCP interface\n"); 219 220 return 0; 221 222 exit_del_pfcp_sock: 223 pfcp_del_sock(pfcp); 224 synchronize_rcu(); 225 exit_err: 226 pfcp->net = NULL; 227 return err; 228 } 229 230 static void __pfcp_dellink(struct net *net, struct net_device *dev, 231 struct list_head *head) 232 { 233 struct pfcp_dev *pfcp = netdev_priv(dev); 234 235 list_del_init(&pfcp->list); 236 unregister_netdevice_queue_net(net, dev, head); 237 } 238 239 static void pfcp_dellink(struct net_device *dev, struct list_head *head) 240 { 241 struct pfcp_dev *pfcp = netdev_priv(dev); 242 struct pfcp_net *pn; 243 244 pn = net_generic(pfcp->net, pfcp_net_id); 245 246 mutex_lock(&pn->lock); 247 if (!list_empty(&pfcp->list)) 248 __pfcp_dellink(dev_net(dev), dev, head); 249 mutex_unlock(&pn->lock); 250 } 251 252 static struct rtnl_link_ops pfcp_link_ops __read_mostly = { 253 .kind = "pfcp", 254 .priv_size = sizeof(struct pfcp_dev), 255 .setup = pfcp_link_setup, 256 .newlink = pfcp_newlink, 257 .dellink = pfcp_dellink, 258 }; 259 260 static int __net_init pfcp_net_init(struct net *net) 261 { 262 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 263 264 INIT_LIST_HEAD(&pn->pfcp_dev_list); 265 mutex_init(&pn->lock); 266 267 return 0; 268 } 269 270 static void __net_exit pfcp_net_exit_rtnl(struct net *net, 271 struct list_head *dev_to_kill) 272 { 273 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 274 struct pfcp_dev *pfcp, *pfcp_next; 275 276 mutex_lock(&pn->lock); 277 278 list_for_each_entry_safe(pfcp, pfcp_next, &pn->pfcp_dev_list, list) 279 __pfcp_dellink(net, pfcp->dev, dev_to_kill); 280 281 mutex_unlock(&pn->lock); 282 } 283 284 static struct pernet_operations pfcp_net_ops = { 285 .init = pfcp_net_init, 286 .exit_rtnl = pfcp_net_exit_rtnl, 287 .id = &pfcp_net_id, 288 .size = sizeof(struct pfcp_net), 289 }; 290 291 static int __init pfcp_init(void) 292 { 293 int err; 294 295 err = register_pernet_subsys(&pfcp_net_ops); 296 if (err) 297 goto exit_err; 298 299 err = rtnl_link_register(&pfcp_link_ops); 300 if (err) 301 goto exit_unregister_subsys; 302 return 0; 303 304 exit_unregister_subsys: 305 unregister_pernet_subsys(&pfcp_net_ops); 306 exit_err: 307 pr_err("loading PFCP module failed: err %d\n", err); 308 return err; 309 } 310 late_initcall(pfcp_init); 311 312 static void __exit pfcp_exit(void) 313 { 314 rtnl_link_unregister(&pfcp_link_ops); 315 unregister_pernet_subsys(&pfcp_net_ops); 316 317 pr_info("PFCP module unloaded\n"); 318 } 319 module_exit(pfcp_exit); 320 321 MODULE_LICENSE("GPL"); 322 MODULE_AUTHOR("Wojciech Drewek <wojciech.drewek@intel.com>"); 323 MODULE_DESCRIPTION("Interface driver for PFCP encapsulated traffic"); 324 MODULE_ALIAS_RTNL_LINK("pfcp"); 325